Inclusion Criteria prior to enrollment:

          -  1. Age > 1 months (with minimum weight of 10 Kg) and < 45 years.

          -  2. Patients deemed eligible for allogeneic HSCT under the originating study, NCT
             04249830

          -  3. Patients with life-threatening hematological malignancies for which HSCT has been
             recommended:

               1. High-risk ALL in 1st CR, ALL in 2nd or subsequent CR;

               2. High-risk AML in 1st CR, AML in 2nd or subsequent CR;

               3. Myelodysplastic syndrome;

               4. JMML (Juvenile myelomonocytic leukemia);

               5. Non-Hodgkin lymphomas in 2nd or subsequent CR;

               6. Other hematologic malignancies eligible for stem cell transplantation per
                  institutional standard.

          -  4. All subjects ≥ 18 years of age must be able to give informed consent, or adults
             lacking capacity to consent must have a LAR available to provide consent. For subjects
             <18 years old their LAR (i.e. parent or guardian) must give informed consent.
             Pediatric subjects will be included in age appropriate discussion and verbal assent
             will be obtained for those > 7 years of age, when appropriate.

        Inclusion criteria prior to T-allo10 infusion:

          1. Patient already received αβdepleted-HSCT and has myeloid engraftment.

          2. Absence of active grade II aGvHD requiring >0.5 mg/Kg of steroids or any diagnosis of
             grade III/IVaGvHD.

        Exclusion Criteria prior to MNC collection for Tallo-10 manufacturing.:

          1. Not eligible to receive HSCT on NCT04249830

          2. Received another investigational agent within 30 days of enrollment.

          3. Pregnancy (positive serum or urine beta-HCG) within 7 days of MNC donation.

          4. Patient or donor is not willing or able to undergo an additional non-mobilized
             apheresis for collection of MNC prior to donation of cells for participation in
             NCT04249830.